JPH0370555B2 - - Google Patents

Description

Claim 1. A substantially horizontally extending chamber in which material is sprayed, an air inlet passage 18 communicating with this chamber, and an air outlet chamber 20 provided in the floor of said chamber and communicating with this chamber. a sub-bed 3, a dividing means 10 for dividing the air outlet chamber into at least two sub-chambers 12, 13, an exhaust air duct 9, 15 communicating with each of the sub-chambers, and supplying cleaning liquid to the sub-bed. means 8, 14 for sucking air carrying the spray material from said chamber through said divided chamber;
and arranged in each of the divided chambers 12 and 13,
cleaning means 2 arranged within said dividing chamber such that the sprayed material flows in friendly contact with the cleaning liquid;
and means 15, 16 for independently controlling the air volume flowing through the respective compartments 12, 13.

2. The dividing means has a dividing plate 10 that extends substantially vertically, and this dividing plate 10 protrudes in the direction of the sub-floor 3 and partially divides the upper surface of the sub-floor 3, and each divided portion The spray booth according to claim 1, wherein the spray booth is a chamber.

3. Each of said cleaning means has a tubular body 2 extending substantially vertically within the respective compartment 12, 13 and penetrating through the sub-bed, with the cleaning liquid being in friendly contact with the air carrying the spray material. 3. The spray booth according to claim 1, further comprising cleaning liquid supply means (4, 11) for supplying cleaning liquid to the sub-bed (3) so as to flow through the tubular body (2).

4. The spray booth according to claim 3, wherein the tubular body 2 protrudes from the sub-floor 3, and a reservoir for cleaning liquid is formed on the upper surface of the sub-floor.

5. The method according to claim 1, wherein the sub-floor 13 is spaced apart above the floor or plate 7, and the tubular body is arranged so that the air and liquid flowing through the tubular body 2 hit the floor or plate. Spray booth listed in either.

6 said air exhaust fans 8, 14 are associated with respective compartments 12, 23 and are arranged to discharge exhaust air into outlet ducts 9, 15 and/or into the atmosphere, dampers 5, 16 etc. 6. A spray booth according to claim 1, wherein a control means is associated with each discharge fan.

7. A common air exhaust fan is provided, communicating with each subchamber by a respective connecting duct, which common fan discharges the exhaust air into the outlet duct and/or into the atmosphere, and where control means such as dampers are provided. A spray booth according to any one of claims 1 to 5, which is combined with each connecting duct.

8 has air supply means 19, 21 for supplying air into the air inlet channel 18, the air supply means comprising an air supply fan 19 and a control damper 2 for controlling the amount of air supplied by this air supply fan;
1. A spray booth according to any preceding claim, comprising: 1.

DETAILED DESCRIPTION The present invention relates to spray booths, and more particularly to spray booths for removing spray material, especially paint, from the exhaust air of the spray booth.

It is common practice to draw air out of a paint spray booth and wash it with a cleaning fluid, typically water, to remove paint contained in the exhaust air. Systems for cleaning the discharge from paint spray booths are described, for example, in British Patent Nos. 1165022, 1399805 and 2007542B, respectively.

The cleaning systems described in these patents are most efficient as the volume of air flowing through the system is constant. If the air volume and air velocity change, the characteristics of the cleaning system will change. This variation therefore creates problems when the volume of air flowing through the paint spray booth changes. The efficiency of this cleaning system deteriorates when the air flow changes appreciably.

There is a need to reduce and substantially reduce the volume of air flow through the booth without adversely affecting the painting operation. Since the air supplied to the booth is conditioned to a predetermined temperature and humidity, reducing the air flow capacity results in substantial energy savings.

When a worker is working in a spray booth,
The downward air velocity is usually at least 0.5 m/
sec. This air velocity is not required for the painting process itself;
When using automatic machines, the air velocity can be reduced to 0.3 m/sec or less.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a spray booth that makes it possible to vary the air flow rate through the booth without impairing the efficiency of the cleaning system.

The spray booth according to the invention comprises a chamber in which the material is sprayed and an air inlet channel communicating with this chamber.
a substantially horizontally extending sub-floor provided on the floor of the chamber and forming an air outlet chamber in communication with the chamber; and a dividing plate dividing the air outlet chamber into at least two divided chambers; an exhaust air duct communicating with each of the divided chambers, a device for supplying cleaning liquid to the sub-bed, means for sucking air carrying spray material from the chamber through the divided chamber; and means for independently controlling the volume of air flowing through each of the divided chambers so that the washed material flows in friendly contact with the cleaning liquid. .

In particular, the cleaning device has a tubular body which extends substantially vertically within each compartment and through the sub-floor. The means for supplying the cleaning liquid distributes the cleaning liquid onto the sub-bed, and the cleaning liquid flows through the tubular body carrying the material and in friendly contact with the air. The tubular body projects with respect to the sub-bed, and a pool of cleaning liquid is formed on the surface of the sub-bed.

In another embodiment, a substantially vertically extending dividing plate projects relative to the sub-floor and divides its surface, the divided parts being associated with respective dividing chambers. Means for separately supplying the cleaning liquid may be provided for each part of the sub-bed.

The tubular body extending through the subbed may have other cross-sectional shapes, such as circular or square, and its dimensions are arbitrary.

The secondary floor is installed at intervals above the main floor or board,
The tubular body is arranged so that the air and liquid flowing inside the tubular body impinge on the main floor or board.

In other embodiments, an air exhaust fan is associated with each compartment and directs the exhaust air to the outlet duct and/or
or arranged to vent to the atmosphere.

Control means, such as dampers, are associated with the exhaust fan.

In other embodiments, a common exhaust fan is provided and is connected to each compartment by a connecting duct.

A common exhaust fan exhausts the exhaust to an outlet duct and/or to the atmosphere. Control means, such as dampers, are associated with each connecting duct.

In particular, the spray booth has means for supplying air to the air inlet channel. For example, the air supply means includes an air supply fan and a control damper arranged to control the volume of air supplied by the air supply fan.

Embodiments of the invention will now be described with reference to the drawings. FIG. 1 is a sectional view of a paint spray booth combined with an embodiment of the present invention, and FIG. 2 is a sectional view taken along the cross-sectional line A in FIG.
It is a top view of the spray booth which shows -A. The illustrated paint spray booth is of a type that paints automobile bodies by moving them using a conveyor (not shown). The object to be coated is coated automatically or manually by spray coating means.

It is common practice to draw air out of a paint spray booth and wash the air with a cleaning fluid to remove paint contained in the exhaust air. Air is supplied to the spray booth through a distributor. Before the air is supplied to the booth, it shall be conditioned by an air conditioning means and shall have a predetermined temperature, humidity, and cleanliness.

In the embodiment shown in FIG. 1, air is supplied to the spray booth through a distributor 18 by a supply fan 19. The amount of air supplied by the fan 19 can be adjusted by a control damper 21. The air supplied to the booth passes around the object being sprayed and carries the paint there. The paint-laden air flows through the floor grate 1 through a substantially vertical exhaust pipe 2 provided in a substantially horizontal sub-floor 3. A sub-floor 3 extends across the booth below the grid 1. The cleaning liquid, generally water that has been chemically treated to make it easier for small paint particles to adhere to water droplets, is transferred to the sub-bed 3 through a pump (not shown), a pipe 4 and a tank 11.
is supplied to Each exhaust pipe 2 protrudes above the sub-floor 3 and stores cleaning liquid in the sub-floor. The cleaning liquid is continuously supplied to the tank 11 and thus to the sub-bed 3, so that the cleaning liquid passes over the upper opening of the exhaust pipe 2 and comes into friendly contact with the air flowing through the exhaust pipe 2. In this way the paint is cleaned from the air.

Each exhaust pipe 2, which may have a circular cross-sectional shape, a planar shape, or another shape, connects each of the physically divided chambers 12, 13 to the upper side of the sub-floor 3. In this connection, the sub-floor 3 forms an outlet chamber 20 below the paint spray chamber, which is divided into two chambers 12, 13 by a vertically extending dividing plate 10.
It is divided into In the illustrated embodiment, the dividing plate 10 extends above the secondary floor surface and divides this surface into a plurality of parts. However, preferably the dividing wall 1
0 may be terminated at subbed 3.

In the illustrated embodiment, each chamber 12 , 13 surrounds a plurality of exhaust pipes 2 . Of course, if the spray booth is limited in length, a single exhaust pipe may be provided for each chamber.

The air-cleaning liquid mixture exiting from each of the exhaust pipes 2 is arranged to impinge on a substrate 7.
The turbulent flow induced by the impact increases the cleaning effect. This base plate 7 forms the lower edge of the air outlet chamber 20 and a dividing plate 10 is supported by this base plate 10.

The chamber 12 is connected to the atmosphere by an exhaust fan and an outlet duct 9. Similarly, the chamber 13 is connected to the atmosphere by an exhaust fan 14 and an outlet duct 15. The air thus leaving the exhaust pipe 2 enters the respective chamber 12 or 13 and is then discharged through the exhaust fan 8 or 14 and the outlet duct 9, 15.

The cleaning liquid loaded with paint flows into a reservoir (not shown) through channels 6,17. The paint is removed from the cleaning fluid by suitable means and recycled to the sub-bed 3 through a pump (not shown) and pipes 4, if necessary. A device for removing pigments from cleaning liquids is described, for example, in GB 1540723.

Each exhaust fan 8, 14 has a control damper 5, 16
It works together with the exhaust fan to control the volume of air sucked out by the exhaust fan. In this way, the dampers 5,16 are used to adjust the volume of airflow flowing through the respective chambers 12,13.

Next, assume that the airflow capacity is 100% when the operator is working inside the spray booth. If painting is carried out automatically while a worker is present in the booth, the required air volume is less, about 60%. In the former case, in order for the operator to carry out manual work, the dampers 5, 16 and the corresponding exhaust fans 8, 14 will suck 60% of the total air flow capacity through one chamber, e.g. chamber 12, and the remaining 40%. is regulated to discharge through the second chamber 13.

When it is necessary to switch the spray booth to automatic operation, the damper 16 is closed and the fan 14 is closed to the chamber 13.
The damper 21 is adjusted to reduce the supply air capacity to 60%. The exhaust fan 8 continues to draw out substantially this volume, ie 60% of the volume. In this way, the airflow flowing through the spray booth starts from 100%.
60%, while the volume of air flowing into the chamber 12 through the exhaust pipe 2 remains essentially constant. In this way, cleaning efficiency within chamber 12 is maintained even when airflow is reduced.

The flow of water into and out of each part of the sub-bed 3 is the same, entering into the pipe 2 by the pipe 4 and the trough 11 and returning by the grooves 6, 17 to the reservoir (not shown).

Obviously, the airflow capacity is determined by closing the chamber 12 by closing the damper 5 and stopping the exhaust fan 8.
By using chamber 13 to extract air from the other spray booth, the original volume can be reduced to 40%. In this case, the volume of air flowing through the exhaust pipe 2 in the chamber 13 is substantially constant and its efficiency is not adversely affected.

It is usually sufficient to physically divide the outlet chamber 20 into a plurality of chambers, each of which is provided with an outlet passage that distributes the total air flow volume through the spray booth in a predetermined proportion. If it is necessary to reduce the airflow through the booth, it is prevented to draw airflow through one of these chambers. Of course, if precise adjustment of the air flow rate is required, a control means such as a static pressure regulator (not shown) may be provided, for example by operating the dampers 5, 16, to control each chamber. This makes it possible to further adjust the airflow capacity.

Of course, two or more separate chambers may be provided, each chamber evacuating a predetermined proportion of the airflow capacity. As the number of rooms increases, the range of use of the system can be increased by increasing the variation in air flow rate. Of course, it goes without saying that this expansion of the range of use will increase the complexity and cost of the entire device.

In the illustrated embodiment, the two chambers 12, 13 are divided by a dividing plate 10, which extends along the longitudinal direction of the spray booth. The exhaust pipe 2 is arranged on one side of this dividing plate 10.

However, a spray booth is of course in which the exhaust pipe 2 is arranged along the longitudinal axis of the booth. In this case, crossed dividing plates are provided, arranged along opposite sides of this person between adjacent exhaust pipes, the dividing plates providing a plurality of exhaust pipes in one chamber and a plurality of exhaust pipes in the other chamber. It is also possible to form two adjacent chambers with the remaining exhaust pipes. In the illustrated embodiment, each of the subchambers has an exhaust system with an exhaust fan and control means therefor. Of course, instead of this, a common exhaust fan may be provided and connected to each chamber by a duct. Each duct connection may require control means, such as a control damper, to control the communication with the chambers as required.